Baby Croup Guide: Barking Cough Symptoms, Home Treatment & When to Go to the ER

Published: 2025-11-03Last Reviewed: 2025-11-03BebeSnap Parenting Team10min read

It is the middle of the night, and your child suddenly starts making a harsh, seal-like barking cough that sounds nothing like any cough you have heard before. Your heart races. This distinctive sound is the hallmark of croup (acute laryngotracheobronchitis), one of the most common respiratory illnesses in young children. Croup primarily affects children between 6 months and 3 years old and peaks during fall and early winter. The good news: most cases are mild and resolve within 3 to 5 days. This guide walks you through recognizing the symptoms, judging severity, managing croup at home, and knowing exactly when to head to the emergency room.

What Is Croup? Causes and Timing

Croup is a viral infection that causes swelling in the larynx (voice box) and trachea (windpipe), narrowing the upper airway. The medical term is acute laryngotracheobronchitis, and it is the inflammation of this narrow passage that produces croup's characteristic symptoms.

Common Cause Viruses

  • Parainfluenza viruses(types 1, 2, 3): responsible for approximately 75% of all croup cases
  • RSV (respiratory syncytial virus)
  • Influenza (flu) virus
  • Adenovirus

Who Gets Croup and When

  • Age: Most common in children aged 6 months to 3 years, can occur up to age 6
  • Season: Peaks in fall (October-November) and early winter
  • Sex: Boys are affected approximately 1.5 times more often than girls
  • Time of day: Symptoms characteristically worsen at night and in the early morning hours

A child's airway is significantly narrower than an adult's, which is why the same degree of swelling that causes only a hoarse voice in an adult can cause serious airway obstruction in a young child. Even 1 millimeter of swelling can reduce an infant's airway opening dramatically.

The 4 Classic Symptoms of Croup

1. Barking Cough

  • A harsh, seal-like or dog-like barking sound — unlike any regular cough
  • The single most recognizable symptom of croup
  • Once you hear it, you will never forget the sound

2. Hoarseness

  • The voice becomes raspy or scratchy due to vocal cord swelling
  • Your child's cry may sound different from normal

3. Stridor

  • A high-pitched squeaking or whistling sound when breathing in
  • This signals that the airway is narrowed
  • If stridor occurs only when crying or agitated, the case is mild; stridor at rest indicates moderate to severe croup

4. Respiratory Distress

  • Visible pulling in of the skin between the ribs, at the collarbone, or below the ribcage with each breath (retractions)
  • Nasal flaring
  • In severe cases, blue discoloration of the lips or fingertips (cyanosis)
💡 Croup symptoms are characteristically worst between midnight and early morning. A child who seems fine during the day can deteriorate rapidly at night. If coughing starts in the evening, monitor closely through the night.

Judging Croup Severity

Treatment depends on how severe the croup is. Use this table to help assess your child's condition.

SeverityCoughStridorBreathingAction
MildOccasional barking coughOnly when crying or agitatedNormal at restHome management
ModerateFrequent barking coughAudible at restMild retractions visibleSee a doctor
SevereSevere coughingLoud stridor at restSignificant retractions, agitationGo to the ER
Impending respiratory failureCough weakeningSounds diminishingAltered consciousness, cyanosisCall 911 immediately
⚠️ Important: As croup progresses toward respiratory failure, the cough and stridor may actually become quieter. Do not mistake silence for improvement. If your child is becoming increasingly lethargic, less responsive, or appears to be "giving up," call 911 immediately.

Croup vs Other Conditions: Key Differences

When your child is coughing and struggling to breathe, it may not always be croup. It is important to distinguish it from these other conditions.

FeatureCroupBronchiolitisEpiglottitisForeign Body Aspiration
OnsetGradual (over 1-2 days)GradualRapid (within hours)Sudden
CoughBarking (seal-like)Wheezy, wetMinimal coughingSudden coughing/gagging
FeverLow to moderateLow to moderateHigh (39°C / 102°F+)Usually absent
DroolingNoneNoneSignificant droolingMay be present
PostureNo specific postureNo specific postureLeaning forward ("tripod")No specific posture
Peak age6 months - 3 yearsUnder 2 years2 - 7 years6 months - 3 years
⚠️ Epiglottitis is a medical emergency. If your child has a high fever, is drooling and unable to swallow, is leaning forward to breathe, and has a muffled voice, call 911 immediately. Do not attempt to look inside the throat.

Home Treatment for Croup

Most mild croup can be managed safely at home. Here is what to do.

1. Keep Your Child Calm — This Is the Most Important Step

Crying and agitation worsen airway swelling, which makes symptoms worse, which causes more crying — a vicious cycle. Stay calm yourself first (your child takes emotional cues from you), then hold your child upright in a comfortable position. Sitting upright makes breathing easier than lying flat.

2. Cool Night Air

Open a window or step outside briefly with your child. Cool air can help constrict the swollen airway tissues and provide relief. Many parents find that by the time they drive to the ER with the car window down, their child's symptoms have already improved significantly.

3. Stay Hydrated

Offer warm fluids, breast milk, or formula in small, frequent sips. Hydration keeps the airway mucosa moist and prevents dehydration, which can worsen symptoms.

4. Use a Humidifier

Running a cool-mist humidifier in your child's room can help reduce airway irritation. Alternatively, run a hot shower in the bathroom and sit with your child in the steamy room for about 10 minutes.

5. Manage Fever

If your child's temperature exceeds 38.5°C (101.3°F), give acetaminophen (Tylenol). For children over 6 months, ibuprofen is also an option. Reducing fever helps your child feel more comfortable and breathe more easily.

What NOT to Do

  • Do not give over-the-counter cough medications (they are ineffective for croup and may have side effects)
  • Do not give honey to children under 1 year (botulism risk)
  • Do not force your child to lie flat (upright is better for breathing)
  • Do not attempt to look inside the throat or insert fingers

When to Go to the Emergency Room

Go to the ER or call 911 immediately if you observe any of the following.

  • Stridor at rest that does not improve with calming and cool air
  • Severe retractions: deep pulling in of the skin around the ribs, collarbone, or neck with every breath
  • Blue or gray lips, fingernails, or skin (cyanosis)
  • Drooling or inability to swallow
  • Child leaning forward and struggling to breathe
  • Decreased alertness — child is unusually sleepy, limp, or unresponsive
  • No improvement after home treatment measures
  • Baby under 3 months showing croup symptoms
⚠️ On the way to the ER: Crack the car window open to let cool outside air flow in. Even if symptoms improve during the drive, always complete the visit. Croup symptoms can return and worsen again quickly.

Medical Treatment for Croup

At the hospital, treatment depends on severity.

Dexamethasone

  • The cornerstone treatment for croup of all severity levels
  • A corticosteroid that effectively reduces airway swelling
  • Typically given as a single oral dose (syrup form)
  • Effects begin within 2 to 4 hours and last 24 to 48 hours
  • Research shows a single dose improves symptoms, reduces return visits, and shortens hospital stays

Nebulized Epinephrine

  • Used for moderate to severe croup
  • Delivered by nebulizer (inhaled mist) to rapidly reduce airway mucosal swelling
  • Works within 10 to 30 minutes
  • Effects last approximately 2 hours, so hospital observation is required after administration

Supplemental Oxygen

  • Used when blood oxygen saturation levels drop below normal

Prevention and Recurrence Patterns

There is no vaccine specifically against croup, but you can reduce the risk of the underlying viral infections.

Prevention Strategies

  • Hand washing: the single most effective preventive measure
  • Cough etiquette: cover coughs and sneezes with the elbow
  • Ventilation: keep indoor spaces well ventilated
  • Avoid close contact with sick individuals
  • Flu vaccination: helps prevent influenza-related croup

Recurrence Patterns

  • Croup can recur, especially in children with naturally narrower airways
  • Frequency typically decreases after age 3 to 4 as the airway grows wider
  • Children who experience croup more than twice per year should see a pediatric pulmonologist
  • Premature birth or a history of intubation increases recurrence risk

Track Your Baby's Health with BebeSnap

Keeping a detailed record of your child's cough patterns, fever history, and symptom changes can make a real difference when speaking with your doctor. BebeSnap makes this easy.

  • Health Tracking: Log cough onset times, fever readings, and symptom progression to give your doctor an accurate picture at every visit
  • AI Chatbot: When your child starts coughing at 2 AM and you are unsure whether to go to the ER, ask our AI for guidance right away
  • Family Sharing: Share your child's health records with your partner or grandparents in real time so whoever is caring for your child has the full picture

FAQ

Q: Is croup contagious?
A: Croup itself is not contagious, but the viruses that cause it (such as parainfluenza) are. When these viruses spread to another child, they may cause a simple cold, croup, or another respiratory illness — it depends on the individual child's anatomy and immune response. Keep your child home from daycare while symptoms are present.

Q: How can I tell a croup cough from a regular cough?
A: A croup cough is unmistakable once you hear it. It sounds like a seal barking or a dog's harsh bark — a loud, metallic, resonant sound that is completely different from the "hack hack" of a regular cold cough. Searching for "croup cough sound" online can help you recognize it before you ever encounter it in person.

Q: Does steam actually help croup?
A: Despite being widely recommended, there is limited scientific evidence that steam inhalation significantly improves croup. What does appear to help more reliably is cool night air. Opening a window or briefly stepping outside with your child can constrict the swollen airway tissue and provide noticeable relief. That said, many doctors still suggest humidification to keep airways moist — it is unlikely to cause harm and may offer some comfort.

Q: How long does croup usually last?
A: Most croup episodes resolve within 3 to 5 days. Symptoms typically peak on the second or third night, then gradually improve. If the cough persists beyond one week or continues to worsen after day 3, consult your pediatrician to rule out other causes.

Q: Does my child need antibiotics for croup?
A: No. Croup is caused by a virus, so antibiotics are not effective. The primary treatment is dexamethasone (a corticosteroid) to reduce airway swelling. Antibiotics may be prescribed only if a secondary bacterial infection develops, which is uncommon.

References

Baby Croup Guide: Barking Cough Symptoms, Home Treatment & When to Go to the ER

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